Nowadays, mobile phones have been more and more widely used with the development of society and the progress of science and technology. The situation has changed from there being only one operator to there being many operators at present, so that the original monopoly has been broken. However, different operators have their own different communication standards.
At present, a widely applied mobile communication standard is a global system for mobile communications (GSM), which is a digital mobile communication standard formulated by the European Telecommunications Standards Institute (ETSI). GSM is short for global system for mobile communications, and an air interface thereof uses a time division multiple access technology. Since being launched into business application from the mid-1990s, the GSM has been used by more than 100 countries around the world. The usage of devices with the GSM standard accounts for more than 80% share in the current global cellular mobile communications device market. The biggest difference between GSM and the previous standards is that signalling and voice channels of GSM are both digital; therefore, GSM is regarded as a second generation (2G) mobile telephone system.
Code division multiple access (CDMA) technology is a new and mature wireless communication technology which is mainly developed on the basis of the spread spectrum communication technology in the digital technology. The principle of the CDMA technology is based on the spread spectrum technology, that is, information data with a certain signal bandwidth and required to be transmitted is modulated with a high-speed pseudo-random code of which the bandwidth is much greater than the signal bandwidth, so that the bandwidth of an original data signal is expanded, and then carrier modulation is performed thereon and the modulated signal is sent out. A receiving end uses a completely identical pseudo-random code to perform correlation processing with the received bandwidth signal, to convert a wideband signal to a narrow-band signal of original information data, that is, despreading, so as to realize data communication.
Wideband code division multiple access (WCDMA) is evolved from code division multiple access (CDMA), and is considered to be a direct expansion of IMT-2000 from the perspective of the official. Compared with generally provided technologies in the existing market, WCDMA can provide a higher data rate for mobile and hand-held wireless devices. WCDMA uses direct sequence-code division multiple access (DS-CDMA) and frequency division duplexing (FDD) modes, wherein the chip rate is 3.84 Mcps, and the carrier bandwidth is 5 MHz. On the basis of Release 99/Release 4 version, 384 kbps user data transmission rate at most can be provided within a 5 MHz bandwidth. WCDMA can support voice, image, data and video communication between mobile/hand-held devices, and the rate can reach 2 Mb/s (for a local area network) or 384 Kb/s (for a wideband network). An input signal is firstly digitized, and then is transmitted in an encoded spread spectrum mode in a relatively wide frequency spectrum range. A narrow-band CDMA uses a carrier frequency of 200 KHz, whereas WCMDA uses a carrier frequency of 5 MHz.
Both the CDMA and the WCDMA use the spread spectrum technology, so that the communication rate of the terminal is greatly improved and is significantly increased compared with the 2G technology, and is thus referred to as a third generation (3G) mobile telephone system.
The above several mainstream standards (including, but being not limited to the above several standards) have their own advantages, and each operators may use one or several mobile communication standards, and communication tariffs thereof are also very different. In order to satisfy the requirements of reducing communication tariffs and realizing the separation of work and life telephones of users, a dual-mode dual-card phone appears.
The dual-mode dual-card phone has two subscriber identity module (SIM) cards, and the two SIM cards may respectively belong to networks with different standards. In order to achieve the purpose of dual-mode dual-card dual-standby, two sets of radio frequency channels are required. At present, the common technical solution is using two radio-frequency chips, respectively a radio-frequency chip 1 and a radio-frequency chip 2, and a switch is adopted to switch to a corresponding network. The specific implementation principle is as shown in FIG. 1. The two SIM cards (SIM_1 and SIM_2) are controlled by the same baseband chip. For a C+G network, there are two radio-frequency chips, and for a W+G network, there is only one radio frequency transceiving chip. The C+G network and the W+G network are both equipped with two sets of transceiving channels. However, there is only one switch used for switching between the networks to communicate (wherein TX is a sent signal, and RX is a received signal). Once a first card in the dual-mode dual-card phone has established a communication, a second card will be in a no service state, which directly results in that a user initiating a communication request to the second card for communication mistakes the mobile phone of the opposite party being in a signal bad state, and the user of the mobile phone will also lose a phone call to the second card during the communication process of the first card. It can be seen from the above-mentioned analysis that, in the related art, since only one radio frequency transceiving chip is arranged in a dual-mode dual-card phone, it would readily result in call loss.
Aiming at the problems above, no effective solution has been presented.